Publications by authors named "John J Liggat"
Article Synopsis
- The study presents the successful creation of new alkali metal dihydropyridines through the metathesis of 1-lithio-2-tbutyl-1,2-dihydropyridine using metal tert-butoxide.
- Five new metallodihydropyridine compounds were isolated and characterized, displaying three different structural forms: a dimer, a dimer of dimers, and a novel polymeric compound.
- Thermal analysis suggests these compounds could serve as simple substitutes for sodium or potassium hydride in reactions, demonstrated through test reactions with benzophenone.
Article Synopsis
- The study investigates the rarely characterized 1-lithio-2-alkyl-1,2-dihydropyridines, which are intermediates in addition reactions involving alkyllithiums and pyridine.
- By using a specific 1:1 ratio of alkyllithium to pyridine and tridentate donors, the researchers successfully stabilized and crystallized a complex with a tert-butyl group.
- The research highlights the importance of stoichiometry, illustrating that altering ratios in reactions can lead to different products, including the hydrolithiation of pyridine by kinetic intermediates.
1-Lithio-2-butyl-1,2-dihydropyridines, typically formed as intermediates in the nucleophilic substitution (addition/elimination) of pyridine with (n- or t-)butyl lithium, have been isolated and comprehensively characterized. The linear substituted isomer is polymeric while the branched substituted isomer is a cyclotrimer. The lower oligomerization of the latter complex confers exceptional hexane solubility making it an excellent lithium hydride source in non-polar, aliphatic media.
View Article and Find Full Text PDFA general thermolysis reaction for the transformation of Group 1 TMP compounds (LiTMP, NaTMP, KTMP) to 1-aza-allylic TTHP derivatives is reported. TMEDA accelerates the reaction and produces the crystalline complexes [(TMEDA)LiTTHP] and [(TMEDA·NaTTHP)2]. Methane elimination during the transformational process was confirmed via TVA coupled to MS.
View Article and Find Full Text PDFColloidal lithography and embossing master are new techniques of producing nanotopography, which have been recently applied to improve tissue response to biomaterials by modifying the surface topography on a nano-scale dimension. A natural polyester (Biopol), 8% 3-hydroxyvalerate-component (D400G) and a conventional biodegradable polycaprolactone (PCL) were studied, both nanostructured and native forms, in vitro and in vivo. Nanopits (100-nm deep, 120-nm diameter) on the D400G surface were produced by the embossing master technique (Nano-D400G), while nanocylinders (160-nm height, 100-nm diameter) on the PCL surface were made by the colloidal lithography technique (Nano-PCL).
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